Carbon diffusion mechanism as an effective stability enhancement strategy:The case study of Ni-based catalyst for photothermal catalytic dry reforming of methane  

碳扩散机制作为有效的稳定性增强策略——以镍基催化剂用于光热催化甲烷干重整为例的研究

作　　者：Dezheng Li Huimin Liu Xuewen Xiao Manqi Zhao Dehua He Yiming Lei 李德正;刘会敏;肖雪文;赵曼淇;贺德华;雷一鸣(辽宁工业大学化学与环境工程学院,辽宁锦州121000;奥赛分子科学研究所(ISMO),巴黎萨克雷大学和国家科学研究中心(CNRS),法国奥赛91400;清华大学化学系,有机光电子与分子工程教育部重点实验室,北京100084;巴塞罗那自治大学理学院化学系(无机化学),萨丹约拉,西班牙巴塞罗那08193)

机构地区：[1]School of Chemical and Environmental Engineering,Liaoning University of Technology,Jinzhou 121000,Liaoning,China [2]Institute of Molecular Sciences of Orsay(ISMO),University Paris-Saclay and National Centre for Scientific Research(CNRS),Orsay,91400,France [3]Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education,Department of Chemistry,Tsinghua University,Beijing 100084,China [4]Department of Chemistry(Inorganic Chemistry),Faculty of Sciences,Autonomous University of Barcelona(UAB),Cerdanyola del Valles,Barcelona 08193,Spain

出　　处：《Chinese Journal of Catalysis》2025年第3期399-409,共11页催化学报(英文)

基　　金：辽宁省青年人才计划(XLYC2203068);辽宁省科技厅科研基金(2022-MS-379);国家自然科学基金(21902116);辽宁省教育厅2024年度基本科研业务费专项资金、国家留学基金(202206250016,202206020087).

摘　　要：Photothermal catalytic methane dry reforming(DRM)technology can convert greenhouse gases(i.e.CH_(4)and CO_(2))into syngas(i.e.H_(2)and CO),providing more opportunities for reducing the greenhouse effect and achieving carbon neutrality.In the DRM field,Ni-based catalysts attract wide attention due to their low cost and high activity.However,the carbon deposition over Ni-based catalysts always leads to rapid deactivation,which is still a main challenge.To improve the long-term stability of Ni-based catalysts,this work proposes a carbon-atom-diffusion strategy under photothermal conditions and investigates its effect on a Zn-doped Ni-based photothermal catalyst(Ni_(3)Zn@CeO_(2)).The photothermal catalytic behavior of Ni_(3)Zn@CeO_(2)can maintain more than 70 h in DRM reaction.And the photocatalytic DRM activity of Ni_(3)Zn@CeO_(2)is 1.2 times higher than thermal catalytic activity.Density functional theory(DFT)calculation and experimental characterizations indicate that Ni_(3)Zn promotes the diffusion of carbon atoms into the Ni_(3)Zn to form the Ni_(3)ZnC0.7 phase with body-centered cubic(bcc)structure,thus inhibiting carbon deposition.Further,in-situ diffuse reflectance infrared Fourier transform(DRIFT)spectroscopy and DFT calculation prove Ni_(3)Zn@CeO_(2)benefits the CH_(4)activation and inhibits the carbon deposition during the DRM process.Through inducing carbon atoms diffusion within the Ni_(3)Zn lattice,this work provides a straightforward and feasible strategy for achieving efficient photothermal catalytic DRM and even other CH_(4)conversion implementations with long-term stability.光热催化甲烷干重整(DRM)技术能够在温和条件下将温室气体(CH_(4)和CO_(2))转化为合成气(H_(2)和CO),为下游化工提供原料,对减少温室效应、实现碳中和具有重要意义.镍(Ni)基催化剂因成本低、催化活性高而备受关注,在DRM领域得到了广泛研究和应用.然而,CH_(4)易在Ni基催化剂表面过度裂解生成沉积碳,导致催化剂迅速失活,严重阻碍了其在光热DRM领域的工业化应用,成为当前亟待解决的关键挑战.为了提升Ni基催化剂的长期稳定性,本文提出了一种碳原子扩散策略,并以锌掺杂镍基催化剂(Ni_(3)Zn@CeO_(2))为例,探究了该策略对Ni基催化剂活性及稳定性的影响.Ni_(3)Zn合金相的设计考虑到引入外部金属原子可以有效地调节Ni晶格参数,从而在间隙位点实现碳原子的扩散.通过共沉淀法以及在H_(2)/N_2气氛下的热还原过程制备了CeO_(2)负载合金化Ni_(3)Zn.X射线衍射(XRD)、透射电子显微镜和高角环形暗场扫描透射电镜表征证实了合金相Ni_(3)Zn成功地锚定在CeO_(2)表面.为了验证这一策略的有效性并探究其机理,将Ni_(3)Zn@CeO_(2)光热催化剂用于长时间DRM反应.结果表明,在光热催化DRM反应中(0.1 g催化剂、500℃、300瓦氙灯照射),Ni_(3)Zn@CeO_(2)具有超过70 h的稳定性,其光热催化DRM活性是热催化活性的1.2倍.光热条件下,初始CH_(4)和CO_(2)转化率分别为536.5和543.4μmol·g^(-1)·min^(-1),H_(2)和CO的释放速率分别为349.9和509.1μmol·g^(-1)·min^(-1).机理研究表明,DRM反应效率的提高应归因于光热效应、CO_(2)强吸附能力和Ni_(3)Zn@CeO_(2)强还原能力之间的协同作用.XRD和密度泛函理论(DFT)计算结果证实,稳定性增强应归因于Ni_(3)Zn空间半径的增加,这有利于碳原子扩散到Ni_(3)Zn八面体中心,原位形成具有体心立方(bcc)结构的Ni_(3)ZnC_(0.7)相,抑制碳沉积现象,成功提高了Ni基催化剂的稳定性.此外,原位漫反射红外傅里叶变换光谱�

关 键 词：Photothermal catalysis Methane dry reforming Ni-based catalyst Stability enhancement Carbon atom diffusion 

分 类 号：O643.36[理学—物理化学] O643.3[理学—化学]